Restarting timer of the presenter console

This use-case came up during this year’s LibreOffice conference. I started the
Impress slideshow a few minutes in advance, so the audience could check if they
are at the correct room, seeing the title side. Right after starting the
slideshow, the presentation timer also started to count. I had to stop and
start the presentation, so I had an idea how much time my talk took so far. The
side effect of this workaround was that the audience saw an ugly short flash
while the presentation was not running at the moment I started talking.

Because hacking the presenter console requires you to have two monitors, it’s
not something I looked into during the conference’s hackfest, but now here it
is: I
added
a button to just restart the timer, then it’s not needed to stop/start the
presentation manually.

The icon is just a placeholder for now, the real design is
in progress.